The rapture of the great multitude and the first resurrection occurs at the seventh (or last) trumpet. The last trumpet (the seventh trumpet) is when the Church is raptured 1Cor 15:52. It also signifies the end of this age and the beginning of the millennium.
The second coming of Christ is at the seventh trumpet. Christ is coming to redeem / harvest the Church from the Earth and to judge the living and the dead.
The last trumpet sounds during the seven bowls of God's wrath which are also known as the third woe. The bowls of God's wrath are poured out on the unbelieving nations (pagans) who have been left behind on Earth after the Church has been taken up to Heaven (Harvested). The bulk of the Church is Harvested after the 1260 day tribulation (post tribulation) but before God pours out his wrath (hence prewrath). Only the 144000 firstfruits are raptured before the Great Tribulation starts (pretribulation rapture of the minority of believers who are mature before the tribulation starts). This is a premillennial view - (the second coming of Christ is just prior to the Millennium) in fact, this is what will cause the Millennium to begin.)

The seventh trumpet therefore encompases the second coming, the rapture of the Church, the third woe which is the seven bowls of God's wrath, the battle of Armageddon, the separation of the sheep and the Goats, the end of this age and the beginning of the millennium.